DTPA renal scan assessment of renal allograft dysfunction in rats

The precise cause of allograft dysfunction after renal transplantation often cannot be established by non-invasive means. In clinical practice, radionuclide scans form an integral part of the clinician's armamentarium in the assessment of these patients [1, 2]. Unfortunately, in the clinical setting more than one pathological process may be responsible for the impaired function, making it difficult to correlate the scan appearances with the pathology. In this study in rats we compared the renal DTPA scan appearances of the various pathological processes which may cause renal allograft dysfunction in the immediate post-transplant period.     

Effects of food restriction and refeeding on adipocyte glucose metabolism in Zucker rats

Chronic food restriction has been shown to enhance glucose metabolism in adipocytes from lean Zucker rats at 10, 26, and 52 weeks of age compared to ad libitum-fed lean rats. Only adipocytes from food restricted 10-week-old obese rats demonstrated this response. In this study, lean and obese rats were food restricted from 5 until 14 weeks of age to determine the age at which adipocytes from obese rats were no longer affected by this intervention. Effects of 1 week of refeeding were also determined. When the rats were killed, body weights were highest in control rats followed by restricted/refed and then restricted rats within each genotype. Epididymal pad weights of lean rats were resistant to dietary intervention, while those of obese-restricted and obese-restricted/refed rats weighed less than pads of obese-control rats. Retroperitoneal pad weight was lowered by food restriction in both genotypes; but only that of lean-restricted/refed rats totally recovered with refeeding. Adipocytes of lean-restricted rats had the highest conversion of glucose to CO₂. Glyceride-glycerol production was higher in obese compared to lean rats, but restricted rats had elevated conversion of glucose to fatty acids. In general, these results indicate that by 14 weeks of age obese Zucker rats no longer respond to food restriction with an elevated rate of glucose metabolism in adipocytes.     

一种改良大鼠异体肾移植模型的建立

目的：为开展器官移植的实验研究，建立大鼠异体肾移植模型。方法：用SD大鼠作为供体和受体，采用原位低温灌注，原位修剪，移植肾放置左侧，血管直接吻合，输尿管带膀胱瓣与膀胱吻合。结果：经过60次的实验，克服了移植物灌注、血管吻合、膀胱吻合等技术难关，建立了稳定实用的肾移植动物模型。手术成功率为80％左右。结论：此模型可以在一般的实验室条件下开展。有较高的成功率，符合肾移植实验研究的需要。     

雌激素对幼年大鼠子宫肌层影响的光镜、组织化学和电镜观察

本文使用常规H—E染色和组织化学方法(PAS反应和甲绿-哌洛宁法)初步观察了雌激素对幼年大鼠子宫壁肌层的细胞形态变化。最显著的变化是:平滑肌细胞体积增大;不仅在子宫壁平滑肌纤维中并且在血管平滑肌细胞中,有大量的PAS阳性颗粒;平滑肌细胞中RNA中度增多。我们也在电镜下观察了它们的超微结构改变。结果表明,实验组的平滑肌细胞和成纤维细胞与对照组相比粗面内质网增多并有池扩张。     

门静脉转流对肝硬化大鼠耐受入肝血流阻断时限的影响

目的：探讨门静脉转流对肝硬化大鼠耐受人肝血流阻断时限的影响。方法：观测门静脉转流与非门静脉转流条件下阻断入肝血流不同时程后动物存活率及肝脏能量代谢的变化，包括肝细胞线粒体呼吸控制率（RCR）、肝组织三磷酸腺苷（ATP）含量、动脉血酮体比值（AKBR）。结果：①术后两周存活率：肝硬化大鼠门静脉转流下入肝血流阻断（PBB）-30min组和PBB-45min组为100%，单纯入肝血流阻断（PTC）-30min组、PBB-60min组分别为65%和75％。②肝脏能量代谢：缺血后肝组织ATP、RCR及AKBR均明显下降。再灌注后上述指标逐渐恢复，但随缺血时间延长，升高幅度明显降低，甚至难以恢复。结论：门静脉转流能显著提高肝硬化大鼠常温下耐受入肝血流阻断的时限。     

Differential effect of oestrogen on post‐exercise cardiac muscle myeloperoxidase and calpain activities in female rats

The effects of oestrogen administration on 1 h post‐exercise cardiac muscle myeloperoxidase (MPO) and calpain activities were determined in female rats. Rats were ovariectomized and implanted for 2 weeks with either oestrogen (25 mg 17‐oestradiol) or placebo pellets or left with ovaries intact. Rats were then run for 1 h at 21 m min^–1, 12% grade, killed 1 h post‐exercise and cardiac muscle and blood samples were removed. Control animals from each group were killed without prior exercise. Serum oestrogen levels in the order of the highest to lowest were; ovariectomized oestrogen replaced rats > intact ovaries rats > ovariectomized placebo rats. Oestrogen induced significant (P < 0.05) elevations in cardiac MPO activity at rest and at 1 h post‐exercise in ovariectomized rats. No significant elevations in cardiac MPO activity were evident in placebo ovariectomized or normal ovary rats at rest or post‐exercise. Cardiac calpain activities were similar in all unexercised groups. Ovariectomized placebo and intact ovary rats had significantly (P < 0.05) elevated cardiac calpain activities 1 h post‐exercise while calpain activity was not significantly elevated in hearts from ovariectomized oestrogen rats. These results demonstrate that oestrogen supplementation in ovariectomized rats induces elevations in cardiac muscle MPO activities at rest and at 1 h post‐exercise. This is opposite to the effect of oestrogen in post‐exercise skeletal muscle and implies a greater neutrophil infiltration into cardiac muscle caused by oestrogen. This effect cannot be explained by changes in 1 h post‐exercise cardiac muscle calpain activity, the elevation of which was suppressed by oestrogen administration. Oestrogen influences cardiac calpain activity similarly to its effect in skeletal muscle. Thus, oestrogen administration to ovariectomized rats induces elevations in cardiac MPO activity while suppressing cardiac calpain activity.     

二硫化碳对大鼠胚胎发育及血清锌和铜含量影响的研究

本文观察了CS_2对大鼠胚胎发育及血清锌、铜含量的影响。发现胚胎着床前死亡率升高,胎鼠皮下出血、心包淤血及骨骼骨化不金的发生率增高。但无明显的致畸效应。14.1及103.9ng/m~3的CS_2对妊娠大鼠的血清锌、铜含量无明显影响。说明CS_2对大鼠的胚胎毒性与其对妊娠大鼠血清锌、铜含量的影响之间没有关联。     

大鼠氮能神经与胃电节律失常的关系

目的 :探讨一氧化氮与胃电节律失常的关系 .方法 :2 8只大鼠随机分为 3组 :正常对照组 (12只 )和胃电节律失常模型组 (8只 )喂养 4wk后 ,先记录胃电、再行胃窦肌间神经丛氮能神经染色 ;药物组 (8只 ) :观察注射不同剂量硝普钠 (SNP)、一氧化氮合酶抑制剂左型精氨酸甲酯 (L NAME)后的胃电变化 .结果 :药物组大鼠注射硝普钠或大剂量L NAME后出现了明显的胃电节律失常 ;模型组大鼠胃电节律失常增加 ,异常节律指数 (ARI)和慢波频率变异系数 (coefficientofvariation,CV)分别为 2 1.8%和 2 5 .7% ,明显高于正常对照组大鼠 (ARI和CV分别为 9.5 %和 17.2 % ,P <0 .0 1) ,胃窦肌间神经丛的氮能神经含量也明显多于正常对照组 (2 1.9%vs13.8% ,P <0 .0 1) .结论 :一氧化氮增多或过少均可导致明显的胃电节律失常     

穹隆-海马伞切断对大鼠脑内TrkA表达的影响

①目的　探讨穹隆 海马伞切断对大鼠脑内不同部位神经生长因子受体TrkA表达的影响及临床意义。②方法　成年健康雌性Wistar大鼠 10只 ,随机分为穹隆 海马伞切断模型组和假手术组。两组大鼠均常规取海马CA1区、皮质区、杏仁复合体区、基底前脑Meynert核等部位脑组织与假手术组比较TrkA阳性细胞表达情况。③结果　假手术组大脑各观察区有基础水平的TrkA表达。模型组大脑海马CA1区、大脑皮质区、杏仁复合体区以及Meynert核区TrkA阳性细胞数明显减少 (t=3.94 4～ 8.4 4 2 ,P <0 .0 5 )。 ④结论　穹隆 海马伞切断可致大鼠脑内多部位TrkA表达减少 ,其可能是导致认知和情绪损伤的原因之一。